When I am training with someone difficult (who constantly corrects, or who corrects me when I am doing what sensei demonstrated), lately I find myself escalating the conflict by throwing the difficult partner harder, or being malicious when applying pins and locks. Usually this results in the partner escalating back, and a couple of times it's gotten too intense.

This behavior is the opposite of what I am training for. I spoke to a couple of sempai about it, and they both said that it's normal, something everyone struggles with. But they had a hard time putting words to how they struggle with it, and made it sound like it just happens and not to worry about it. But I don't want to incorporate this into my personality. I'd rather figure out how to control myself when people piss me off.

How normal is this? How do other people work through it? I don't think of myself as being otherwise vindictive or violent, and have never physically confronted someone before these on-the-mat scenarios, which are kind of like fights but not really. In the rest of my life I think of myself as being fairly easy going--I am not afraid of confrontation, but am certainly not one to pick a fight.

Hi,
Being the gentleman that I am I can tell you that on the few occasions this situation has occurred in my Aikido career I initially used to fight fire with fire.If the guy wanted a war he got one.After a while I got fed up with this and later when it happened again[I a guy was throwing me in a break arm shiho nage] I had a quiet word in his ear indicating if he did it again I would do him.He responded favourably and we parted with a new understanding of the rules of engagement.Another occasion I recall was a violent confrontation with a young Japanese guy.Nearly feather dusters at hundred yards.We were separated by Fujita Sensei, the class teacher at the time.
Rather than get caught up in a death match , move away and just ignore the guy.If he comes back, you know he is looking for trouble.At that point make a decision.
Good luck , Joe.